1. Technical Field
The present subject matter relates to detecting and counteracting attempts to reprogram semiconductor devices that store secure information. More particularly, the subject matter relates to using an error correction code programmed into the semiconductor device to detect attempts at altering the original programmed values.
2. Background
Manufacturers have become increasingly aware of the need to make mobile communication devices secure. In recent years there has been a significant increase in attempts by unscrupulous individuals to intercept communications from such devices in order to capture identification information unique to each mobile communication device. Once captured, this information may then be used to re-program a similar mobile communication device. The use of such a “cloned” mobile communication device (e.g., a cellular telephone) may result in charges being assessed against the owner of the original device for services utilized by the operator of the cloned device.
Manufacturers of mobile communication devices have attempted to address the problem by utilizing electrically programmable fuses, also known as “e-fuses,” to program security related information (e.g., encryption keys and device identification numbers) into semiconductor devices. The use of e-fuses was intended to prevent later re-programming of security related information. But advances in technology and increases in the sophistication of the unscrupulous individuals engaging in the cloning of mobile electronic devices has resulted in the development of techniques for reprogramming e-fuses, something that was previously thought to be either impossible or beyond the abilities of those individuals engaging in such cloning activities.
Accordingly, a system capable of detecting that an e-fuse based or other similar device has been re-programmed, and which is also capable of either restoring the original programmed value or of preventing operation of the reprogrammed device is desirable.